Pneumatic motor mechanism.



P. H. FORMAN.

PNEUMATIC MOTOR MECHANISM. APPLICATION HLE D MAR. a, 1912.

Patented May 23, 1916.

I}. mm

PARIS R. FORMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO NATIONAL PNEUMATIC I COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF WEST VIRGINIA.

PNEUMATIC MOTOR MECHANISM.

Specification of Letters Yatent.

Application filed March 8, 1912. Serial No. 682,526.

'1 0 all whom it may concern.

Be it known that I, PARIS R. FORMAX, a citizen of the United States, residing at Chicago, county of Cook, and State of Illinois, have made a certain new and useful Invention in Pneumatic Motor Mechanism, of which the following is a specification.

This invention relates to pneumatic motor mechanism.

The object of the invention is to provide a pneumatic motor mechanism which is simple in construction and efficient in operation. I

Other objects of the invention will appear more fully hereinafter.

The invention'consists substantially in the construction, combination, location and relative arrangement of parts. all as will be more fully hereinafter set forth as shown in the accompanying drawing' and finally pointed out in the appended claims.

Referring to the accompanying drawing, and to the various views and reference signs appearing thereon,-Figure 1 is a view in longitudinal central section taken through the ports 2 and 4, Fig. 2, of a pneumatic motor mechanism embodying the principles of my invention. Fig. 2 a view in end elevation'of the valve seat employed in connection with my invention. Fig. 3 is a view in section on the line 3, 3, Fig. 1, looking in the direction of the arrows and showing the relationof the valve ports with reference to the seat ports with. which the valve ports coiiperate. Fig. 4 is a view similar to Fig. 3, taken on the samesection line. showing a displaced position of the valve and its .ports as will be more fully hereinafter explained. Figs. 5,6, 7 and 8 are diagrammatic views illustrating modified forms of valves, adapted for use in connection with my invention.

In carrying out my invention I employ two cylinders 5, 6, of relatively different areas, the larger cylinder being designated by reference sign 5, and the smaller cylinder by reference sign 6. In the particular form shown. to which however, my invention. as defined in the claims, is not to be limited or restricted, the cylinders 6, are arranged in axialalinement with each other, and are open-ended'at the proximate ends thereof.

"Operating'in these cylinders are pistons which in the case of the lay-"er cylinder 5 at 1, 2', 3, 4, (see Figs. 3 and 4).

comprises the heads 7, 8, and in the case of the smaller cylinder 6, comprises the heads 9, 10. Where the cylinders 5, 6, are arranged in line with each other a' common PlStOIlI'Od 11, is employed which extends through the open proximate ends of the cylindersv and carries the'piston heads 7, 8, 9, 10. The piston heads 7 8, are suitably spaced apart upon the rod 11, by a spacing sleeve 14:. Similarly a spacing sleeve 15, interposed between the piston heads 9, 10, serves to separate the same. Also mounted upon and connected to the piston-rod 11, is a cross-head 16. This cross head may be separated from the piston head 8, by means of a spacing sleeve 17 and also from the piston head 9, by a similar spacing sleeve 18. The clamp nuts at the ends of the piston rod serve to clamp these several parts together on saidrod. The closed end of the smaller cylinder 6, is in communication with a supply tank for compressed 'air, or other operating medium Patented May 23, 1916.

through a pipe connection 19, which communicates with the interior of the cylinder 6, at two points, one point being indicated at 20, intermediate the ends of the cylinder, this being a port of large area, and at the point 21, closely adjacent the closed end of said cylinder through a port ofsmall area. These ports 20,21, are in constant communication with the pressure supply source or tank and no control or valve mechanism therefor is necessary.

It is necessary to control the supply'and exhaust of the operating medium to and from the closed end of cylinder 5. This control, is effected by means of a valve mechanism comprising a cap 25, within which is vided with suitable port openings, indicated The valve 26, coiiperates with a valve seat or surface 27 (see Fig. 2) being the outer surface of the closed head 28, of the cylinder 5. In this valve surface or head 28 are formed ports, passages 01 openings 1, 2, 3, 4, with which respectively cooperate the valve ports 1. 2, 3 4%. The valve is provided with ducts or passages 29 and 30, which respectively connectthe ports 1*, 2 or the ports 3. l as indicated in dotted lines in 'Figs. 3

and '4. .The valve '26 is held to its seatagainst the surface 27, in any suitable or convenient manner, preferably by means of mounted the valve 26. The valve 26 is pro- I a spring 31, arranged within a cup 32 arranged within the cap 25, (see Fig. 1). The cup 32 is provided with a rod 33, by which said cup may be axially rotated. A pin or other form of projection 34:, cafried by the cup 32, engaging with lugs 35, on the valve, serves to rotate said valve when said cup, or its actuating rod 33, is rotated. The port 4, in the valve seat 27, communicates with the interior of the closed end of the cylinder 5, as shown in Fig. 1. The port marked 3, in Fig. 2, communicates with the source of pressure supply or tank or other convenient source, through a pipe connection 36. The port 1, communicates through a suitable connection to exhaust. Through the'head 28, is formed a port opening or passage 2. shown also in Fig. 2, and said port opening communicates with a passage 22, with which communicates a port 36, of large area, opening into the cylinder at a point intermediate its ends, and also a port 23, of small area which opens into the cylinder 5, adjacent to the closed end thereof. The dotted lines shown in Fig. 2 as connecting certain ports, indicate the two positions of the valve 26.

The cylinders 55, 6, may be supported in assembled relation in any suitable or convenient manner. A simple and efficient support for said cylinders is shown wherein said cylinders are swaged into rings 37, 38, forming portions of a supporting base 39. Similarly, the passage or duct 22 may be formed in a casting 40, which is also swaged upon the cylinder 5, by means of rings or bands 41, encircling said cylinder. Thecross head 16 may be connected in any suitable or convenient manner with'the part to be moved or operated by the motor.

A pneumatic motor mechanism embody ing the principles of my invention is particularly well adapted for the operation of doors. In this particular use of motor mechanism of my invention, I employ a pivoted lever 42, connected to the cross-head 16, and having rods 4-3, 44; connected to said lever 42, on opposite sides of its pivot point 45, said rods being respectively connected to the door sections or panels or other parts to be operated. Of course, other suitable forms of connecting mechanism to the part to be operated may be employed and will readily suggest themselves in the details thereof to persons skilled in the art.

The operation of amiotor mechanism embodying the principles of my invention is very simple and will be readily understood. The pressure medium is constantly supplied to the closed end of the smaller cylinder 6. In the position of the parts as indicated in Fig. 1, the piston heads are at the left hand limit of their movement or stroke. In this position the door or other part to be moved is in one of the limits of its movement. In

this positionpressure medium is acting upon the smaller pistons 9, 10, from the pressure supply source or tank, and serves to retain the door or other part in its corresponding limit of movement. Now it it is desired to operate the door, or other part'to be moved, in the opposite direction, the valve 26, is actuated so as to bring the ports 1", and 2*, respectively, into communication with the valve seat ports 3, 4. This operation will open the source of pressure supply from the tank to the cylinder 5 through the connection 36, port 3, of the valve seat, port 1" of the valve duct or passage 29. port 2 of the valve and port r, into the closed end of the larger cylinder The door or other part to be moved will thereupon take up its movement rapidly, the excess of area of the p stons 7, 8, over that of the pistons 9, 10, causing the pistons to be shifted or.moved toward the right. During this movement the pressure contained in the closed end of cylinder 6, is forced back into the pressure tank, at first through the. large area port opening 20, as well as through the smaller area of opening 21, thereby insuring a rap-id initial movement of the door or other part to be moved. As the piston heads 9, 10, continue to travel toward the right they eventually cover the large exhaust port 20, of cylinder 6, and thereafter the exhaust from the closed stantly applied in the closed end of cylinder 6 and which constantly tends to return or restore the pistons toward, the left when the closed end of the larger cylinder'5 is open to exhaust. This is a beneficial arrangement as it secures a smooth easy working of the part to be moved. After operating the apparatus in the manner above described, ifit is desired to shift or move the door or other part again toward the left, the valve 26', is actuated so as to bring the ports 4, 3 and the duct 30, respectively into communication with the valve seat ports 2 and 1. This movement opens the closed end of the larger cylinder 5, to exhaust, While at the same time cutting off the tank pressure by closing the port 3, as well as the port 4. By bringing the valve seat ports 2 and 1 into communication with each other the closed end ot'the larger cylinder 5, is opened to full and free exhaust; at first through the lax-gr exhaust port opening 36, and channel 22. thereby insuring a rapid initial movement toward closing pogition, for instance, of the door. or other part to be moved, but

smaller port opening 23, and consequently the final closing movement or final movementof the part to be moved, is eflected against the cushioning action afforded by the restricted exhaust of the medium concontained in the closed end of the cylinder through the port 23, of the small area.

'It will be seen that only two positions of the valve 26 are necessary, one where the ports 3, 4:, are brought into communication with each other, or with the ports 1, and 2, of the valve seat and the other position being that of the valve-Which brings the port 1, 2, thereof into communication with the ports 3, and 4,.of the valve seat.

It will be seen that the valve, as Well the seat with which it cotiperates, is provided with four port openings in the face thereof, the ports in the valve face being connected in pairs by ducts or channels 29, 30. In the arrangement shown in Figs. 5

and 6, the valve is provided with only. two

port openings, these being connected by a duct or channel 40, while in Figs. 7 and 8, the valve is shown as having'three port openings all connected by ducts or channels 41, 42.

7 My invention, therefore, in its broadest scope, as defined in the claims, is not to be limited in respect to the particular structure of valve employed. 1

In the arrangement of Fig. 5 the valve, is in position for the seat ports ,1 and 2 to ho brought into communication with each other. This cuts oii the pressure supply to the large cylinder and opens the same to exhaust, first through the large area of passage 22, and finally through the small area of duct 23. In Fig. 6, the valve is in po-.

sition to open communication between seat ports 3 and 4. flhis cuts oh the exhaust connections and supplies pressure to the cylinder.

It may sometimes be desired to omit the small exhaust passage 23, from the cylinder, and to employ a passage of reduced area in the valve itself to accomplish the same function. This is the arrangement shown in Figs. 7 and 8. The duct or passage 42 is formed in the valve and communicateswith the larger duct or passage 41, iherein so as to connect up all the valve rts. In Fig. 7 the valve is shown in 'pois moved into the position indicated in Fig. 8

then the pressure is freely admitted into the end of the cylinder through port 3, passage 41, and port 4, and would also pass to some extent through the small area passage 42 and port 2 and thence'into the space between pistons 7 and 8, there equalizing against the piston surfaces and hence not causing any trouble. It is obvious that the valve may be operated in any suitable or convenient manner and from any suitable or convenient point.

A pneumatic motor mechanism embodying the principles of construction above described and indicated, is not only simple and eilicient, but is exceedingly economical to manufacture, and may be readily and easily assembled and installed. The parts are few and easily manufactured,.thereby very greatly redi icing the cost and the expense of manufacture of motors of this nature. 1

tively operating in each of said cylinders,

each pair of said pistons being connected together through the open ends of the cylinders and to the. part to be moved, the closed end of one of said cylinders being constantly in communication with a source of supply of operating medium through a portof large area, communicating with the cylinder at a point intermediate the ends of said cylinder, and also through a port of small area at the closed end thereof, and means for controlling the supply and exhaust of operating medium to and from the closed end of the other cylinder. V

2. In a pneumatic motor mechanism, differential cylinders, each having a closed and parts to be moved, the closed end of thesmaller of said cylinders being constantly in communication with a source of supply of operatingmedium through two ports, one of said ports being of large area, and the other of small-area, the port of large area being located intermediate the ends of said cylinders and the port of small area being located adjacent the closed end of said cylinder and means for controlling the supply and exhaust of operating medium to and from theclosed end of the other or larger cylinder,

3. In a pneumatic motor mechanism, differential cylinders independent of and arranged in alinement ,with each other closed at their remote, and open at their proximate ends, a pair of spaced apart pistons respectively operating in each of said independent cylinsource of supply of operating medium, and

means for controlling the supply and exhaust of operating medium to and from the closed end of the other cylinder.

4-. In a pneumatic motor mechanism, differential cylinders independent of and arranged in alinement with each other, a pair of spaced apart pistons respectively operatmg in each of said independent cylinders,

a piston rod common to said pistons, a cross head connected to said piston rod and connected to the part to be moved, the cylinder of smaller area being constantly in communication through a plurality of ports at relatively different distances from the closed end thereof with a source of supply, and means for controlling the supply and exhaust of operating medium to and from the other cylinder.

In a pneumatic motor mechanism, differential cylinders arranged in alinement with each other, closed at their remote and open at their proximate ends. a pair of spaced apart pistons respectively operating in each of said cylinders, a piston rod common to said cylinders, a cross head connected to said piston rod and adapted to be connected to the part to be moved, the smaller cylinder being constantly in communication at its closed end with a source of supply of operating medium through two ports. one of said ports being of large area, and located at a point intermediate the ends of said-cylinder. and the other of said ports being of restricted area, and communicating with the cylinder at a point adjacent its closed end. and means for controlling the supply and exhaust of operating medium to and from the closed end of the larger cylinder.

(3. In a pneumatic motor mechanism, differential cylinders, each having a closed and v I anopen end, a pair of spaced apart plstons respectively operating in each of said cylinders, said pistons being connectedto the part to be moved, one of said cylinders being constantly in communication at its closed end with a source of supply of operating nledium, a valve for controlling the supply and exhaust of operating medium to and from the closed end of the other cylinder and having pressure supply and exhaust port openings, and exhaust openings respectively of large and small area communieating with the interior of said last mentioned cylinder, and controlled by said valve,

the exhaust port of large area communicating with the cylinder intermediate the ends of said cylinder.

7. In a pneumatic motor mechanism, differential cylinders each having a closed and an open end, and arranged in alinement with each other, a pair of spaced apart pistons respectively operating in each of said cylinders, a piston rod common to said pistons, a cross head connected to said piston rod and adapted to be connected to the part to be moved, one of said cylinders being constantly in communication at its closed end with a source of supply of operating medium, a valve for controlling the supply and exhaust of operating medium to and from the closed end of the other cylinder and having pressure supply and exhaust port openings, and exhaust'openings respectively of large and small area communicating with the interior of said other cylinder, and controlled by said valve, the exhaust port of larger area communicating with the cylinder intermediate the ends of said cylinder and the exhaust port of small area located at the closed end of said cylinder.

8. In a pneumatic motor mechanism, differential cylinders, connected pistons respectively operating in said cylinders, said pistons being connected to the part to be moved, one ofsaid cylinders being constantly in connnunication with a souce of supply of operating medium, a closed headfor the other of said cylinders, said closed. head having port openings therethrough, and the outer surface thereof forming a valve seat,

a valve fitted to said seat and having ports the other irylinder, a supporting base for said cylinders, and rings swaged upon said cylin ders to form a supporting connection there,- for with said base.

10. In a pneumatic motor mechanism,

differential cylinders each having a closed" and an open end, a pair of spaced apart and connected pistons respectively operating in each of said cylinders, said pistons being connected to the part to be moved, each-of said cylinders having a port opening of large area intermediate its ends and a port of small area adjacent its closed end, one of said cylinders being inconstant communication through both its large and small port other of said port openings openings with ajsoure e' of pressure supply, and means forf'controlling the supply and exhaust of operating medium to and from the other of said cylinders.

fill. In a pneumatic motor mechanism, differential cylinders, each having a. closed and an open end, a pair of spaced apart and termediate the ends of sald cylinder, and the ed area and located adjacent theclo'sed end of said cylinder, and, a valve mechanism for controlling said portv openings.

12. In a pneumatic motor mechanism, dif- 7 having an open and a closed end, and arranged in alinement with each other, a pair of spaced apart pisferential cylinders each tons respectively operating in said cylinders,

va, piston rod common to said cylinders and operating through the open proximate ends of said'cylinders, a cross head connected to said piston rod and adapted to be connected to the part to be moved, one of sa1d cyl 1nders being constantly in communication with a source of supply of operating medium through ports, one of which is of large area and located intermediate the ends of said cylinder and the other being of restrlcted area and located adjacent the closed end of said cylinder, a supply port opening for the closed end of the other of said cylinders, and exhaust ports communicating with said other cylinder, one of said exhaust ports being of large area, and communicating with said cylinder at a point intermediate its ends and the other of said exhaust ports being of restricted area and communicating with said cylinder adjacent its closed end,

beingof restricts 'spectively operating and avalve mechanism for controllingsaid port openings.

13. In a pneumatic motor mechanism, two cylinders arranged in alinement with each other, pistons respectively operating in said cylinders, said pistons having a common connecting rod operating through the open proximate ends of said cylinders, a cross head connected to said piston rod and adapted to be connected-to the part to be moved, the cylinder of smaller'size having p'ort openings in constant communication with a source of pressure supply, one of said port openings being of large area and located 'intermediatethe ends of said cylinder, and

the other of said port openings being of restricted area and located adjacent the closed end of said cylinder, the closed end of said larger cylinder having a (pressure supply port opening and exhaust port openings, one of the latter being of lar er area and located the other of said exhaust openings-being of restricted area, and located adjacent the closed end of said cylinder, and a valve for controlling said port openings.

'14. In a pneumatic motor mechanism, differential cylinders, connected pistons rein said cylinders, said pistons being connected to the part to be moved, one of said cylinders being constantly in communication with a souroe'of supply of operating medium, means for controlling the supply and exhaust of operating medium to the other cylinder, a supporting base for said cylinders and rings swaged upon one of said cylinders and having an exhaust passage through the body thereof, and communicating with said cylinder at a point intermediate its ends.

In testimony whereof I have. hereunto set my hand in the presence of the subscrib-' PARIS R. FORMAN.

\Vitnesses IV. HOWELL, E. H. Donuon, L. M. SHIELDS.

intermediate the ends 0 said cylinder, and 

